High hydrogen desorption temperature and sluggish reaction kinetics are the major limitations for the practical application of MgH

2

. In this study

Co particles with a face centered cubic (FCC) structure and a hexagonal close packed (HCP) structure were prepared facilely and proved to be good catalysts for magnesium hydride. Co particles with FCC structure presented better catalytic effect on MgH

2

than that with HCP structure. Both 7% (mass) Co FCC and HCP particle modified MgH

2

decreased the initial dehydrogenation temperature from 301.3 ℃ to approximately 195.0 ℃

but 7% (mass) Co with FCC structure modified MgH

2

has a faster desorption rate

and around 6.5% (mass) H

2

was desorbed in 10 min at 325 ℃. Hydrogen uptake was detected at 70 ℃ under 3.25 MPa hydrogen pressure and 6.0% (mass) H

2

was recharged in 40 min at 150 ℃. The hydrogen desorption and absorption activation energy for 7% (mass) FCC Co modified MgH

2

was significantly decreased to (76.6±8.3) kJ·mol

-1

and (68.3±6.0) kJ·mol

-1

respectively. Thermodynamic property was also studied

the plateau pressures of MgH

2

+ 7% (mass) FCC Co were determined to be 0.14

0.28

0.53 and 0.98 MPa for 300 ℃

325 ℃

350 ℃ and 375℃. The decomposition enthalpy of hydrogen (Δ

H

) for MgH

2

+ 7% (mass) FCC Co was (80.6±0.1) kJ·mol

-1

5.8 kJ·mol

-1

lower than that of

as-prepared MgH

2

. Moreover

cycling performance for the first 20 cycles revealed that the reaction kinetics and capacity of MgH

2

-FCC Co composite remained almost unchanged. The result of density functional theory calculation demonstrated that cobalt could extract the Mg—H bond and reduced the decompose energy of magnesium hydride. Our paper can be presented as a reference for searching highly effective catalysts for hydrogen storage and other energy-related research fields.